Adjusting post_save User model import

[mauricioabreu]

Moved post_save signal to init.
Added noqa flake8 to ignore unused imports.

[coveralls]

Coverage increased (+0.33%) when pulling b8ec639 on mauricioabreu:fix-user-model-import into 551f172 on mfogel:develop.

[mfogel]

Thanks for the pull request. I see two parts to it.

The first the NOQA markings for flake8 - I think I've addressed that since this PR was made on develop by adding an __all__ to the module. Please verify.

The second - django 1.7 best practices with the signal registration - it looks like the best practice is explained here: https://docs.djangoproject.com/en/dev/topics/signals/#django.dispatch.receiver Looking at that, I'm thinking something like

if getattr(settings, 'SIMPLE_EMAIL_CONFIRMATION_AUTO_ADD', True):
    @reciever(post_save, sender=get_user_model())
    def auto_add(sender, **kwargs):
        # same as before

in simple_email_confirmation/signals.py

Then, per https://docs.djangoproject.com/en/dev/ref/applications/#configuring-applications we should define a AppConfig subclass that imports signals.py in it's ready() method. Also, default_app_config should be configured to point to that AppConfig subclass.

Final, I think the signal definitions currently in simple_email_confirmation/signals.py should probably be moved to models.py to ensure they're always imported, even in django < 1.7.

Thoughts?